Ethylene interpolymer

ABSTRACT

Metallic complexes having indenyl ligands can be used as an ingredient of a catalyst system. The catalyst system can be used in polymerizations of ethylenically unsaturated hydrocarbon monomers that include both olefins and polyenes. Embodiments of the catalyst system can provide interpolymers that include polyene mer and from 40 to 75 mole percent ethylene mer, with a plurality of the ethylene mer being randomly distributed. The catalyst system also can be used in solution polymerizations conducted in C5-C12 alkanes, yielding interpolymers that include at least 10 mole percent ethylene mer.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional application of U.S. patent application Ser. No.15/315,011, which issued as U.S. Pat. No. 10,457,765 on 29 Oct. 2019,which is a national stage entry of international patent appl.PCT/US2015/032373, filed 26 May 2015, which claims the benefit of U.S.provisional application Nos. 62/006,119, filed 31 May 2014, and62/136,302, filed 20 Mar. 2015, the disclosures of all of which areincorporated herein by reference.

BACKGROUND INFORMATION

Rubber goods such as tire treads often are made from elastomericcompositions that contain one or more reinforcing materials such as, forexample, particulate carbon black and silica; see, e.g., The VanderbiltRubber Handbook, 13th ed. (1990), pp. 603-04.

Good traction and resistance to abrasion are primary considerations fortire treads; however, motor vehicle fuel efficiency concerns argue for aminimization in their rolling resistance, which correlates with areduction in hysteresis and heat build-up during operation of the tire.Reduced hysteresis and traction are, to a great extent, competingconsiderations: treads made from compositions designed to provide goodroad traction usually exhibit increased rolling resistance and viceversa.

Filler(s), polymer(s), and additives typically are chosen so as toprovide an acceptable compromise or balance of these properties.Ensuring that reinforcing filler(s) are well dispersed throughout theelastomeric material(s) both enhances processability and acts to improvephysical properties. Dispersion of fillers can be improved by increasingtheir interaction with the elastomer(s), which commonly results inreductions in hysteresis (see above). Examples of efforts of this typeinclude high temperature mixing in the presence of selectively reactivepromoters, surface oxidation of compounding materials, surface grafting,and chemically modifying the polymer, typically at a terminus thereof.

Various natural and synthetic elastomeric materials often are used inthe manufacture of vulcanizates such as, e.g., tire components. Some ofthe most commonly employed synthetic materials include high-cispolybutadiene, often made by processes employing catalysts, andsubstantially random styrene/butadiene interpolymers, often made byprocesses employing free radical or anionic initiators.

Of particular difficulty to synthesize are interpolymers of olefins andpolyenes, particularly conjugated dienes, due in large part to the verydifferent reactivities of those two types of ethylenically unsaturatedmonomers. Their respective susceptibilities to coordinate with the metalatoms of polymerization catalysts differ greatly.

Although difficult to synthesize, such interpolymers are of significantcommercial interest. Because polyene and olefin monomers usuallyoriginate from different raw materials and are provided via differenttechniques, manufacturers of elastomeric materials can guard againstsupply and price disruptions of either monomer by synthesizinginterpolymers with varying and/or adjustable amounts of mer from each.

Additionally, certain portions of pneumatic tires, particularlysidewalls, preferably exhibit good resistance to atmosphericdegradation, particularly ozone degradation. Such components can benefitfrom inclusion of substantially saturated elastomer(s). Historically,typical options have included ethylene/propylene/non-conjugated diene(EPDM) interpolymers or brominated copolymers of isobutylene andpara-methylstyrene. Alternatives to these materials also remaindesirable.

SUMMARY

Any of a class of indenyl-metal complexes can be used as an ingredientof a catalyst system. The catalyst system can be used in polymerizationsof ethylenically unsaturated hydrocarbon monomers, including mixtures orblends of polyenes and olefins.

The class of metallic complexes can be represented by the generalformula

where M represents a Group 3 metal atom; L represents a neutral Lewisbase; z is an integer of from 0 to 3 inclusive; m is 1 or 2 with theproviso that, when m=2, the silyl groups are at the 1 and 3 positions ofthe indenyl ligand; n is 1 or 2; each R¹ independently is H, a halogenatom, a C₁-C₂₀ alkyl group, a C₅-C₈ cycloalkyl group, an aralkyl group,an alkoxy group, a siloxy group, a nitro group, a sulfonate group, or a—(CH₂)_(y)R³ group where y is 0 or 1 and R³ is a substituted orunsubstituted aryl group; and R² is an X-type, monoanionic ligand. An Lgroup and an R² group optionally can join so as to provide, togetherwith the M atom to which each is bonded, a cyclic moiety. Alternativelyor additionally, two R¹ groups can join to form a substituted orunsubstituted hydrocarbylene group that, together to the Si atom, canform a cyclic moiety.

Aspects of the invention include a catalyst composition that includesthe formula (I) complex, certain of which also involve a catalystactivator, as well as methods of making both the complex and thecatalyst composition.

In a further aspect is provided a process of polymerizing ethylenicallyunsaturated hydrocarbon monomers which involves contacting the monomerswith the aforedescribed catalyst composition. The ethylenicallyunsaturated hydrocarbon monomers can include one or more types ofpolyene, including dienes, and, in some embodiments, the resulting dienemer advantageously can incorporate preferentially in a1,4-configuration, i.e., the polymer product can have low amounts ofvinyl mer. The ethylenically unsaturated hydrocarbon monomers also caninclude one or more types of olefin and, in some embodiments, theresulting polymer can include large amounts of olefin mer (e.g., atleast about 50 mole percent) which, in many embodiments, can beincorporated substantially random throughout the polymer chain or, inother embodiments, can be present in a block of randomly distributedolefin and polyene mer. In certain embodiments, the process can beconducted in a solvent system that is primarily, or even completely,composed of C₅-C₁₀ alkanes. In these and other embodiments, the processoptionally can include providing the resulting polymer with a terminalmoiety that includes one or more heteroatoms, a step that can enhancethe ability of a polymer to interact with a variety of types ofparticulate fillers.

In yet another aspect is provided a polyene/olefin interpolymer thatincludes a high amount of olefin mer. When the olefin is or includesethylene, the interpolymer can contain from ˜40 to ˜75 mole percentethylene mer, with a plurality of such ethylene mer being randomlydistributed. Additionally, when the polyene is a conjugated diene, atleast 40%, at least 45% or even at least 50% of the conjugated dienemer, relative to the total moles of diene mer, can have a cis isomericconfiguration. In some embodiments, the polyene/olefin interpolymer caninclude at least one block of polyene mer and a block of randomlydistributed polyene and olefin mer. A particular embodiment of thisaspect is a conjugated diene/ethylene copolymer wherein one block hasconjugated diene mer having the amount of cis isomeric configurationdescribed above and another block having randomly distributed conjugateddiene and ethylene mer.

In a still further aspect is provided a composition that includes aninterpolymer in a solvent system that includes at least 50 weightpercent of one or more C₅-C₁₀ alkanes and, in some embodiments, includesonly such C₅-C₁₀ alkanes. The interpolymer component includes polyenemer and at least 10 mole percent ethylene mer. A plurality of theethylene mer can be randomly distributed in the interpolymer.

The foregoing polymerization processes also optionally can includeproviding the resulting polymer with a terminal moiety that includes oneor more heteroatoms so as to enhance the ability of the polymer tointeract with a variety of types of particulate filler such as, e.g.,carbon black and/or silica.

Also provided are compositions, including vulcanizates, that includeparticulate fillers and the resulting polymers, certain embodiments ofwhich may also include terminal functionality, as are methods ofproviding and using such compositions.

Other aspects of the invention will be apparent to the ordinarilyskilled artisan from the detailed description that follows. To assist inunderstanding that description, certain definitions are providedimmediately below, and these are intended to apply throughout unless thesurrounding text explicitly indicates a contrary intention:

-   -   “polymer” means the polymerization product of one or more        monomers and is inclusive of homo-, co-, ter-, tetra-polymers,        etc.;    -   “mer” and “mer unit” both mean that portion of a polymer derived        from a single reactant molecule (e.g., ethylene mer has the        general formula —CH₂CH₂—);    -   “copolymer” means a polymer that includes mer units derived from        two reactants, typically monomers, and is inclusive of random,        block, segmented, graft, etc., copolymers;    -   “interpolymer” means a polymer that includes mer units derived        from at least two reactants, typically monomers, and is        inclusive of copolymers, terpolymers, tetra-polymers, and the        like;    -   “substituted” means containing a heteroatom or functionality        (e.g., hydrocarbyl group) that does not interfere with the        intended purpose of the group in question;    -   “polyene” means a molecule, typically a monomer, with at least        two double bonds located in the longest portion or chain        thereof, and specifically is inclusive of dienes, trienes, and        the like;    -   “polydiene” means a polymer that includes mer units from one or        more dienes;    -   “lanthanide metal” means any element having an atomic number of        57-71 inclusive;    -   “Group 3 metal” means Sc, Y or a lanthanide series metal;    -   “phr” means parts by weight (pbw) per 100 pbw rubber;    -   “radical” means the portion of a molecule that remains after        reacting with another molecule, regardless of whether any atoms        are gained or lost as a result of the reaction;    -   “neutral Lewis base” means a non-ionic compound (or radical)        that includes an available pair of electrons;    -   “aryl” means a phenyl or polycyclic aromatic radical;    -   “aralkyl” means an alkyl radical that includes an aryl        substituent, e.g., a benzyl group;    -   “non-coordinating anion” means a sterically bulky anion that        does not form coordinate bonds with, for example, the active        center of a catalyst system due to steric hindrance;    -   “non-coordinating anion precursor” means a compound that is able        to form a non-coordinating anion under reaction conditions;    -   “terminus” means an end of a polymeric chain;    -   “terminally active” means a polymer with a living or        pseudo-living terminus; and    -   “terminal moiety” means a group or functionality located at a        terminus.

Throughout this document, all values given in the form of percentagesare weight percentages unless the surrounding text explicitly indicatesa contrary intention. The relevant portion(s) of any specificallyreferenced patent and/or published patent application are incorporatedherein by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a heat flow vs. temperature plot obtained by differentialscanning calorimetry (DSC) on the polymer from Example 3.

FIG. 2 is proton nuclear magnetic resonance (NMR) spectrograph of thepolymer from Example 3.

FIG. 3 is ¹³C NMR spectrograph of the polymer from Example 3.

FIG. 4 is a heat flow vs. temperature DSC plot on the polymer fromExample 16.

FIG. 5 is ¹H NMR spectrograph of the polymer from Example 16.

FIG. 6 is ¹³C NMR spectrograph of the polymer from Example 16.

FIG. 7 is a heat flow vs. temperature DSC plot on the polymer fromExample 24.

FIG. 8 is ¹H NMR spectrograph of the polymer from Example 24.

FIG. 9 is ¹³C NMR spectrograph of the polymer from Example 24.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

As apparent from the foregoing, the catalyst composition can be used topolymerize one or more types of polyenes, optionally but in somerespects preferably in combination with one or more types of olefins.

The resulting polymer can be elastomeric, including mer that themselvesinclude ethylenic unsaturation. Mer units that include ethylenicunsaturation can be derived from polyenes, particularly dienes andtrienes (e.g., myrcene). Illustrative polyenes include C₄-C₃₀ dienes,preferably C₄-C₁₂ dienes. Preferred among these are conjugated dienessuch as, but not limited to, 1,3-butadiene, 1,3-pentadiene,1,3-hexadiene, 1,3-octadiene, 2,3-dimethyl-1,3-butadiene,2-ethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene,4-methyl-1,3-pentadiene, 2,4-hexadiene, and the like.

Polymers having overall 1,2-microstructures of no more than 50%,preferably no more than 35%, based on total moles of polyene mer isconsidered to be “substantially linear.” Certain end use applicationsargue for even lower amounts of 1,2-linkages, e.g., less than 20%, lessthan 15%, or even less than 10%. The present catalyst compositions havebeen found to be capable of providing polymers that have from ˜2 to ˜10%1,2-linkages.

Those polyene mer not incorporating into a polymer chain in a vinyl(1,2-) configuration can have either a cis or trans isomericconfiguration. Polymers that have high cis-1,4-linkage contents aredesirable for certain end use applications but can be difficult orinefficient to achieve via free radical or anionic (living)polymerizations. Polymers with high amounts of cis-1,4 diene mer,therefore, commonly are prepared by processes using selective catalysts.

The present process can provide polymers with polydiene mer having acis-1,4-linkage content of ˜40% to ˜70%, typically ˜45% to ˜60%, witheach of the foregoing representing a numerical percentage relative tototal number of mer. While these percentages are not as high as seen inpolymers prepared using other catalyst systems, the polymers that resultfrom the present process have other characteristics not previouslyobtainable via previously known processes.

Examples of olefins that can be employed in the polymerization processinclude C₂-C₃₀, preferably C₂-C₂₀ and more preferably C₂-C₁₂, straightchain or branched α-olefins such as ethylene, propylene, 1-butene,1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene,3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene,1-hexadecene, 1-octadecene, 1-eicosene, and the like, as well as C₃-C₃₀cycloolefins such as cyclopentene, cycloheptene, norbornene,5-methyl-2-norbornene, and tetracyclododecene. In several embodiments,ethylene constitutes a preferred olefin.

The polymerization process can provide olefin/polyene interpolymershaving a wide range of amounts of each type of mer, i.e., embodiments ofthe process employing certain formula (I)-type complexes in a catalystsystem can result in interpolymers having predominant amounts of polyenemer, e.g., olefin/conjugated diene copolymers that include moreconjugated diene mer than olefin mer, while embodiments of the processemploying catalyst systems that involve certain other formula (I)-typecomplexes can result in interpolymers having predominant amounts ofolefin mer. Resulting interpolymers can contain at least 10, 20, 30, 40,50, 60 or even up to 70% olefin mer, even where the interpolymers areprepared in solvent systems that contain predominantly or only C₅-C₁₀alkanes. (All of the foregoing percentages are mole percents, and it isenvisioned to combine these percentages into pairs so as to form ranges,e.g., at least 10 to 70%, at least 10 to 60%, at least 20 to 70%, etc.)

The number average molecular weight (M_(n)) of a polymer producedaccording to the disclosed methods typically is such that a quenchedsample exhibits a gum Mooney viscosity (ML₁₊₄/100° C.) of from ˜2 to˜150, more commonly from ˜2.5 to ˜125, even more commonly from ˜5 to˜100, and most commonly from ˜10 to ˜75; the foregoing generallycorresponds to a M_(n) of from ˜5,000 to ˜250,000 Daltons, commonly from˜10,000 to ˜150,000 Daltons, more commonly from ˜50,000 to ˜120,000Daltons, and most commonly from ˜10,000 to ˜100,000 Daltons or even˜10,000 to ˜80,000 Daltons. The resulting interpolymer typically has amolecular weight distribution (M_(w)/M_(n)) of from 1 to 20, commonlyfrom 2 to 15, and more commonly from 3 to 10. (Both M_(n) and M_(w) canbe determined by GPC using polystyrene standards for calibration.)

The foregoing types of polymers can be made by solution polymerization,which affords exceptional control of properties as randomness,microstructure, etc. Solution polymerizations have been performed sinceabout the mid-20th century, so the general aspects thereof are known tothe ordinarily skilled artisan; nevertheless, certain aspects areprovided here for convenience of reference.

Suitable solvents include those organic compounds that do not undergopolymerization or incorporation into propagating polymer chains (i.e.,are inert toward and unaffected by the catalyst composition) andpreferably are liquid at ambient temperature and pressure. Examples ofsuitable organic solvents include hydrocarbons with relatively lowboiling points such as aromatic hydrocarbons including benzene andtoluene as well as (cyclo)aliphatic hydrocarbons such as, e.g.,cyclohexane. Exemplary polymerization solvents also include variousC₅-C₁₂ cyclic and acyclic alkanes (e.g., n-pentane, n-hexane, n-heptane,n-octane, n-nonane, n-decane, isopentane, isohexanes, isooctanes,2,2-dimethylbutane, cyclopentane, cyclohexane, methylcyclopentane,methylcyclohexane, etc.) as well as their alkylated derivatives, certainliquid aromatic compounds (e.g., benzene, toluene, xylenes,ethylbenzene, diethylbenzene, and mesitylene), petroleum ether,kerosene, petroleum spirits, and mixtures thereof. Other potentiallysuitable organic compounds that can be used as solvents includehigh-boiling hydrocarbons of high molecular weights such as paraffinicoil, aromatic oil, or other hydrocarbon oils that are commonly used tooil-extend polymers. The ordinarily skilled artisan is aware of otheruseful solvent options and combinations.

Advantageously, in certain embodiments, a solution polymerization can beperformed in a solvent system that includes at least 50% (by wt.) of oneor more C₅-C₁₀ alkanes, preferably C₅-C₁₀ linear alkanes. In certain ofthese embodiments, the solvent system can include only such C₅-C₁₀linear alkanes. Advantageously, embodiments of the polymerizationprocess conducted in a solvent system that is mostly or only C₅-C₁₀linear alkanes can yield polymers having high levels of olefin mer,e.g., a diene/ethylene interpolymer having at least 10, at least 15, atleast 20, at least 25, at least 33, at least 40 or even at least 50 molepercent ethylene mer.

As described previously, the polymerization process employs a catalystcomposition that includes a particular class of Group 3 metal complexes.The term “catalyst composition” encompasses a simple mixture ofingredients, a complex of various ingredients that results from physicalor chemical forces of attraction, a chemical reaction product of some orall of the ingredients, or a combination of the foregoing.

Exemplary catalyst compositions include (a) a formula (I) complex, analkylating agent and optionally a halogen-containing compound (whereneither the formula (I) complex or the alkylating agent contains ahalogen atom); (b) a formula (I) complex and an aluminoxane; or (c) aformula (I) complex, an alkylating agent, and a non-coordinating anionor precursor thereof. Certain embodiments of a formula (I) complex mightbe able to be used alone as a catalyst. Each component of theseexemplary compositions is discussed separately below.

The polymerization processes described herein employ a specific genus ofGroup 3 metal complexes, specifically, those defined by formula (I) setforth above. The complex can be formed prior to introduction to thepolymerization vessel, or components (reactants) can be added separatelyand permitted to react so as to form the complex, and therefore thecatalyst, in situ.

In formula (I), M represents a Group 3 metal atom. Where M is alanthanide series metal, it preferably is Nd or Gd. M can be in any of anumber of oxidation states, with +2 to +5 being common and +3 beingperhaps the most common.

Again referring to formula (I), L represents a neutral Lewis base,examples of which include but are not limited to cyclic or acyclic(thio)ethers, amines, and phosphines. Specific non-limiting examples ofL groups include THF, diethyl ether, dimethyl aniline, trimethylphosphine, neutral olefins, neutral diolefins, and the like. Use ofethers and cyclic ethers as L in formula (I) complexes can be preferred.

Again referring to formula (I), z can be an integer of from 0 to 3(determined by the available coordination number(s) of M), so thecomplex can contain no L groups, one L group, or a plurality of Lgroups. In some embodiments, preference can be given to complexes wherez is 0; examples of such embodiments are given below in the examplessection. Where z is 2 or 3, each L can be the same or different,although preference can be given to those complexes where each L is thesame.

Again referring to formula (I), each R² independently is an X-type,monoanionic ligand (of the CBC method, see Green, M. L. H., “A newapproach to the formal classification of covalent compounds of theelements,” J. Organomet. Chem., 500 (1-2), pp. 127-48 (1995)).Non-limiting examples of R² include H; a halogen atom, especially Cl orBr; a silyl group; a siloxy group; a nitro group; a sulfonate group; anamido group; a silylalkyl group; an alkoxy, particularly a C₁-C₆ alkoxy,group; and a C₁-C₂₀, particularly a C₁-C₁₂, substituted orunsubstituted, straight-chain or branched (perfluoro)alkyl group(including, but not limited to, methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, neopentyl, n-hexyl, andoctyl), aralkyl group, allyl group, amino group or substituted orunsubstituted aryl group (including, but not limited to, phenyl, tolyl,benzyl, naphthyl, biphenyl, phenanthryl, anthracenyl and terphenyl). Al-and B-containing groups represented, respectively, by AlR⁷ ₄ and BR⁷ ₄where R⁷ is H, a halogen atom, a substituted or unsubstituted arylgroup, etc., also can serve as an R² group. Those embodiments where R²bonds to or associates with M via a C atom might permit the use ofsimpler catalysts systems, a point discussed in more detail below. Anyof a variety of bis(silyl) amino groups constitute preferred R² groupsin certain embodiments.

For substituted R² groups, exemplary substituents include, but are notlimited to halogen atoms, halo-substituted groups (e.g., halogenatedC₁-C₃₀, particularly C₁-C₈, hydrocarbyl groups such as trifluoromethyl,pentafluorophenyl, and chlorophenyl), other C₁-C₃₀, particularly C₁-C₈,hydrocarbyl groups (e.g., aryl-substituted alkyl groups such as benzyland cumyl), heteroatom-containing groups (e.g., alkoxy, aryloxy such as2,6-dimethylphenoxy or 2,4,6-trimethylphenoxy, acyl such asp-chlorobenzoyl or p-methoxybenzoyl, (thio)carboxyl, carbonato, hydroxy,peroxy, (thio)ester such as acetyloxy or benzoyloxy, (thio)ether,anhydride, amino, imino, amide such as acetamido or N-methylacetamido,imide such as acetimido and benzimido, hydrazino, hydrazono, nitro,nitroso, (iso)cyano, (thio)cyanic acid ester, amidino, diazo, borandiyl,borantriyl, diboranyl, mercapto, dithioester, alkylthio, arylthio suchas (methyl)phenylthio or naphthylthio, thioacyl, isothiocyanic acidester, sulfonester, sulfonamide, dithiocarboxyl, sulfo, sulfonyl,sulfinyl, sulfenyl, sulfonate, phosphido, (thio)phosphoryl, phosphato,silyl, siloxy, hydrocarbyl-substituted silyl groups such as methylsilyl,dimethylsilyl, trimethylsilyl, ethylsilyl, diethylsilyl, triethylsilyl,diphenylmethylsilyl, triphenylsilyl, dimethylphenylsilyl,dimethyl-t-butylsilyl, dimethyl(pentafluorophenyl)silyl,bistrimethylsilylmethyl, and hydrocarbyl-substituted siloxy groups suchas trimethylsiloxy), and the like. (Replacing the silicon atom in theSi-containing groups with Ge or Sn can provide useful Ge- orSn-containing groups.)

Alternatively, one R² and one L, together with the M atom, can join toform a cyclic moiety, typically a 5- or 6-membered ring that optionallycontains one or more heteroatoms in addition to the M atom. Optionally,the cyclic moiety can include one or more pendent substituents such as,but not limited to, substituted or unsubstituted aryl and C₁-C₂₀(particularly C₁-C₆) alkyl groups.

Again referring to formula (I), each R¹ independently is H, a halogenatom, a C₁-C₂₀ (particularly C₁-C₆) alkyl group, a C₅-C₈ cycloalkylgroup, an aralkyl group, an alkoxy group, a siloxy group, a nitro group,a sulfonate group, or a —(CH₂)_(y)R³ group where y is 0 or 1 and whereR³ is a substituted or unsubstituted aryl group, preferably a phenylgroup.

Where R³ of a —(CH₂)_(y)R³ group is an alkyl-substituted phenyl group,the position of the alkyl substituent can impact the properties of theresulting polymer, e.g., a methyl group at the 4-position of the phenylring can yield a polymer with more isolated polyene mer than ananalogous complex with a methyl group at the 2-position. The term“isolated” relates to the numerical amount of polyene mer not adjacentto at least one other polyene mer, as evidenced by peak(s) at ˜32.1and/or ˜32.2 ppm in a ¹³C NMR spectroscopy plot and/or by peak(s) atbetween ˜1.85 and ˜2.02 ppm in a ¹H NMR spectroscopy plot. Thepercentage of such isolated polyene mer can be calculated by dividingthe heights of the peaks at these shifts by the sum of the heights ofall peaks due to polyene mer, e.g., all peaks between ˜1.85 and ˜2.20ppm for ¹H NMR and peaks at ˜27.3, 32.1, 32.2, and 32.4 ppm for ¹³C NMR.

In certain embodiments, all R¹ groups can be selected from alkyl and—(CH₂)_(y)R³ groups; in certain of these, as well as other embodiments,all R¹ groups can be the same.

Generally, formula (I)-type complexes where each R¹ is an alkyl group,regardless of whether each R¹ is the same is different, tend to yieldpolymers with the lowest levels of vinyl mer, i.e., diene mer having1,2-microstructure.

Formula (I)-type complexes where at least one R¹ is a —(CH₂)R³ group,particularly a substituted or unsubstituted benzyl group, have beenfound to be capable of producing polymers having unusual and verydesirable properties. For example, while these types of complexes canprovide olefin/polyene interpolymers having a high amounts of polyenemer incorporated in a 1,4-configuration, those interpolymers can berandom (i.e., few to no blocks of either olefin or polyene mer andhaving large amounts of isolated polyene mer) or can include a block ofpolyene mer along with at least one segment (a block or microblock) thathas randomly distributed polyene and olefin mer; advantageously, theblock interpolymer embodiments can be achieved without the need forstaged addition of different monomers, although such staged addition isnot excluded from the process of the present invention. Additionally oralternatively, these types of complexes can result in interpolymershaving higher amounts of ethylene than can analogous complexes notincluding at least one —(CH₂)R³ group as an R¹.

While the amount of isolated polyene mer typically is quite low, i.e.,usually less than 10 mole percent, commonly less than ˜5 mole percentand often less than 1 mole percent, formula (I)-type complexes where atleast one R¹ is a —(CH₂)R³ group can produce polymers where the amountof such “isolated” polyene mer is quite high i.e., typically more than25 mole percent, commonly more than ˜30 mole percent and often more than40 mole percent; in certain embodiments, the amount of such “isolated”polyene mer can be above 75, 80 or even 85 mole percent. (Allpercentages in this paragraph are based on the total moles of polyenemer.)

Two R¹ groups, together with the Si atom to which each is bonded,optionally can join to form a cyclic moiety, typically a 5- or6-membered ring that optionally contains one or more heteroatoms inaddition to the M atom. Optionally, the cyclic moiety can include one ormore pendent substituents such as, but not limited to, substituted orunsubstituted C₁-C₆ alkyl groups.

For R¹, R² and R³, exemplary substituents include, but are not limitedto halogen atoms, halo-substituted groups (e.g., halogenated C₁-C₃₀hydrocarbyl groups such as trifluoromethyl, pentafluorophenyl, andchlorophenyl), other hydrocarbyl groups (e.g., aryl-substituted alkylgroups such as benzyl and cumyl), heteroatom-containing groups (e.g.,alkoxy, aryloxy such as 2,6-dimethylphenoxy or 2,4,6-trimethylphenoxy,acyl such as p-chlorobenzoyl or p-methoxybenzoyl, (thio)carboxyl,carbonato, hydroxy, peroxy, (thio)ester such as acetyloxy or benzoyloxy,(thio)ether, anhydride, amino, imino, amide such as acetamido orN-methylacetamido, imide such as acetimido and benzimido, hydrazino,hydrazono, nitro, nitroso, cyano, isocyano, (thio)cyanic acid ester,amidino, diazo, borandiyl, borantriyl, diboranyl, mercapto, dithioester,alkylthio, arylthio such as (methyl)phenylthio, or naphthylthio,thioacyl, isothiocyanic acid ester, sulfonester, sulfonamide,dithiocarboxyl, sulfo, sulfonyl, sulfinyl, sulfenyl, phosphido,(thio)phosphoryl, phosphato, silyl, siloxy, hydrocarbyl-substitutedsilyl groups such as methylsilyl, dimethylsilyl, trimethylsilyl,ethylsilyl, diethylsilyl, triethylsilyl, diphenylmethylsilyl,triphenylsilyl, dimethylphenylsilyl, dimethyl-t-butylsilyl,dimethyl(pentafluorophenyl)silyl, bistrimethylsilylmethyl, andhydrocarbyl-substituted siloxy groups such as trimethylsiloxy), and thelike. (Replacing the silicon atom in the Si-containing groups with Ge orSn can provide useful Ge- or Sn-containing groups.) The Al- andB-containing groups can be represented, respectively, by AlR⁷ ₄ and BR⁷₄ where R⁷ is H, a halogen atom, a substituted or unsubstituted arylgroup, etc.

Again referring to formula (I), the variable n can be either 1 or 2,with the resulting complexes being represented below by, respectively,formulas (Ia) and (Ib):

Depending on the value of z, M in the formula (Ia) complexes can beinvolved in from 3 to 6 bonds. The coordination numbers of Group 3 metalatoms, particularly lanthanide metal atoms, in organometallic complexescan range from 3 to 12, with the bulkiness of the ligands being theprimary deciding factor on the upper limit. Such metal atoms typicallyhave a coordination number of at least 6, but bulky ligands can resultin lower coordination numbers. Therefore, particularly where R² is arelatively bulky ligand, z might be limited to 0 to 2 inclusive, or even0 or 1.

The values of both n and z also can impact the identity of the R²group(s). For example, where n=2 and/or z≥1, a bis(trialkylsilyl) aminogroup as an R² group might be too bulky to permit the complex to besynthesized, at least efficiently or in high yields. Thus, one of thealkyl groups attached to the silyl Si atom might need to be replacedwith a smaller group or atom, e.g., an H atom. (This is intended to bean exemplary teaching, which the ordinarily skilled artisan can use toguide selection of appropriate number and types of ligands.)

The variable m in formula (I)-type complexes is 1 or 2. When m=2, the—SiR¹ ₃ groups typically are located at the 1 and 3 positions of theindenyl ligand. Using the formula (Ia) complex above for exemplarypurposes, this can be represented as follows:

The ordinarily skilled artisan easily can extend this description toenvision the substitutions on the general formula (Ib)-type bis-indenylcomplexes.

Formula (I)-type complexes can be prepared by known procedures, examplesof which are described in the examples section below, the teaching ofwhich can be extended or modified readily by the ordinarily skilledartisan.

Component (b) of the catalyst composition, referred to herein as aco-catalyst or catalyst activator, includes an alkylating agent and/or acompound containing a non-coordinating anion or a non-coordinating anionprecursor.

An alkylating agent can be considered to be an organometallic compoundthat can transfer hydrocarbyl groups to another metal. These agentstypically are organometallic compounds of electropositive metals such asGroups 1, 2, and 13 metals. Exemplary alkylating agents includeorganoaluminum compounds such as those having the general formula AlR⁸_(o)X_(3-o) where o is an integer of from 1 to 3 inclusive; each R⁸independently is a monovalent organic group, which may containheteroatoms such as N, O, B, Si, S, P, and the like, connected to the Alatom via a C atom; and each X independently is H, a halogen atom, acarboxylate group, an alkoxide group, or an aryloxide group. In one ormore embodiments, each R⁸ independently can be a hydrocarbyl group suchas, for example, alkyl, cycloalkyl, substituted cycloalkyl, alkenyl,cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, aralkyl,alkaryl, allyl, and alkynyl groups, with each group containing from asingle C atom, or the appropriate minimum number of C atoms to form thegroup, up to about 20 C atoms. These hydrocarbyl groups may containheteroatoms including, but not limited to, N, O, B, Si, S, and P atoms.Non-limiting species of organoaluminum compounds within this generalformula include

-   -   trihydrocarbylaluminum compounds such as trimethylaluminum,        triethylaluminum, triisobutylaluminum (TIBA),        tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum,        tri-t-butylaluminum, tri-n-pentylaluminum, trineopentylaluminum,        tri-n-hexylaluminum, tri-n-octylaluminum,        tris(2-ethylhexyl)aluminum, tricyclohexylaluminum,        tris(1-methylcyclopentyl)aluminum, triphenylaluminum,        tri-p-tolylaluminum, tris(2,6-dimethylphenyl)aluminum,        tribenzylaluminum, diethylphenylaluminum,        diethyl-p-tolylaluminum, diethylbenzylaluminum,        ethyldiphenylaluminum, ethyldi-p-tolylaluminum, and        ethyldibenzylaluminum;    -   dihydrocarbylaluminum hydrides such as diethylaluminum hydride,        di-n-propylaluminum hydride, diisopropylaluminum hydride,        di-n-butylaluminum hydride, diisobutylaluminum hydride (DIBAH),        di-n-octylaluminum hydride, diphenylaluminum hydride,        di-p-tolylaluminum hydride, dibenzylaluminum hydride,        phenylethylaluminum hydride, phenyl-n-propylaluminum hydride,        phenylisopropylaluminum hydride, phenyl-n-butylaluminum hydride,        phenylisobutylaluminum hydride, phenyl-n-octylaluminum hydride,        p-tolylethylaluminum hydride, p-tolyl-n-propylaluminum hydride,        p-tolylisopropylaluminum hydride, p-tolyl-n-butylaluminum        hydride, p-tolylisobutylaluminum hydride,        p-tolyl-n-octylaluminum hydride, benzylethylaluminum hydride,        benzyl-n-propylaluminum hydride, benzylisopropylaluminum        hydride, benzyl-n-butylaluminum hydride, benzylisobutylaluminum        hydride, and benzyl-n-octylaluminum hydride;    -   hydrocarbylaluminum dihydrides such as ethylaluminum dihydride,        n-propylaluminum dihydride, isopropylaluminum dihydride,        n-butylaluminum dihydride, isobutylaluminum dihydride, and        n-octylaluminum dihydride;    -   dihydrocarbylaluminum carboxylates;    -   hydrocarbylaluminum bis(carboxylate)s;    -   dihydrocarbylaluminum alkoxides;    -   hydrocarbylaluminum dialkoxides;    -   dihydrocarbylaluminum halides such as diethylaluminum chloride        (DEAC), di-n-propylaluminum chloride, diisopropylaluminum        chloride, di-n-butylaluminum chloride, diisobutylaluminum        chloride, di-n-octylaluminum chloride, diphenylaluminum        chloride, di-p-tolylaluminum chloride, dibenzylaluminum        chloride, phenylethylaluminum chloride, phenyl-n-propylaluminum        chloride, phenylisopropylaluminum chloride,        phenyl-n-butylaluminum chloride, phenylisobutylaluminum        chloride, phenyl-n-octylaluminum chloride, p-tolylethylaluminum        chloride, p-tolyl-n-propylaluminum chloride,        p-tolylisopropylaluminum chloride, p-tolyl-n-butylaluminum        chloride, p-tolylisobutylaluminum chloride,        p-tolyl-noctylaluminum chloride, benzylethylaluminum chloride,        benzyl-n-propylaluminum chloride, benzylisopropylaluminum        chloride, benzyl-n-butylaluminum chloride,        benzylisobutylaluminum chloride, and benzyl-n-octylaluminum        chloride;    -   hydrocarbylaluminum dihalides such as ethylaluminum dichloride,        n-propylaluminum dichloride, isopropylaluminum dichloride,        n-butylaluminum dichloride, isobutylaluminum dichloride, and        n-octylaluminum dichloride;    -   dihydrocarbylaluminum aryloxides; and    -   hydrocarbylaluminum diaryloxides.        In certain embodiments, the alkylating agent can include        trihydrocarbylaluminum, dihydrocarbylaluminum hydride, and/or        hydrocarbylaluminum dihydride.

Other organoaluminum compounds that can serve as alkylating agentsinclude, but are not limited to, dimethylaluminum hexanoate,diethylaluminum octoate, diisobutylaluminum 2-ethylhexanoate,dimethylaluminum neodecanoate, diethylaluminum stearate,diisobutylaluminum oleate, methylaluminum bis(hexanoate), ethylaluminumbis(octoate), isobutylaluminum bis(2-ethylhexanoate), methylaluminumbis(neodecanoate), ethylaluminum bis(stearate), isobutylaluminumbis(oleate), dimethylaluminum methoxide, diethylaluminum methoxide,diisobutylaluminum methoxide, dimethylaluminum ethoxide, diethylaluminumethoxide, diisobutylaluminum ethoxide, dimethylaluminum phenoxide,diethylaluminum phenoxide, diisobutylaluminium phenoxide, methylaluminumdimethoxide, ethylaluminum dimethoxide, isobutylaluminum dimethoxide,methylaluminum diethoxide, ethylaluminum diethoxide, isobutylaluminumdiethoxide, methylaluminum diphenoxide, ethylaluminum diphenoxide, andisobutylaluminum diphenoxide.

Aluminoxanes constitute another class of organoaluminum compoundssuitable for use as an alkylating agent. (These compounds also can serveas activators after the alkylating activity is complete.) This classincludes oligomeric linear aluminoxanes and oligomeric cyclicaluminoxanes, formulas for both being provided in a variety ofreferences including, for example, U.S. Pat. No. 8,017,695. (Where theoligomeric type of compound is used as an alkylating agent, the numberof moles refers to the number of moles of Al atoms rather than thenumber of moles of oligomeric molecules, a convention commonly employedin the art of catalyst systems utilizing aluminoxanes.)

Aluminoxanes can be prepared by reacting trihydrocarbylaluminumcompounds with water. This reaction can be performed according to knownmethods such as, for example, (1) dissolving the trihydrocarbylaluminumcompound in an organic solvent and then contacting it with water, (2)reacting the trihydrocarbylaluminum compound with water ofcrystallization contained in, for example, metal salts, or wateradsorbed in inorganic or organic compounds, or (3) reacting thetrihydrocarbylaluminum compound with water in the presence of themonomer(s) to be polymerized.

Suitable aluminoxane compounds include, but are not limited to,methylaluminoxane (MAO), modified methylaluminoxane (MMAO, formed bysubstituting ˜20 to 80% of the methyl groups of MAO with C₂-C₁₂hydrocarbyl groups, preferably with isobutyl groups, using knowntechniques), ethylaluminoxane, n-propylaluminoxane,isopropylaluminoxane, butylaluminoxane, isobutylaluminoxane,n-pentylaluminoxane, neopentylaluminoxane, n-hexylaluminoxane,n-octylaluminoxane, 2-ethylhexylaluminoxane, cyclohexylaluminoxane,1-methylcyclopentylaluminoxane, phenylaluminoxane, and2,6-dimethylphenylaluminoxane.

Aluminoxanes can be used alone or in combination with otherorganoaluminum compounds. In one embodiment, MAO and at least one otherorganoaluminum compound such as DIBAH can be employed in combination.The interested reader is directed to U.S. Pat. No. 8,017,695 for otherexamples of aluminoxanes and organoaluminum compounds employed incombination.

Also suitable as alkylating agents are organozinc (particularly dialkylzinc) compounds as well as organomagnesium compounds such as thosehaving the general formula R⁹ _(g)MgX_(2-g) where X is defined as above,g is 1 or 2, and R⁹ is the same as R⁸ except that each monovalentorganic group is connected to the Mg atom via a C atom. Potentiallyuseful organomagnesium compounds include, but are not limited to,diethylmagnesium, di-n-propylmagnesium, diisopropylmagnesium,dibutylmagnesium, dihexylmagnesium, diphenylmagnesium,dibenzylmagnesium, hydrocarbylmagnesium hydride (e.g., methylmagnesiumhydride, ethylmagnesium hydride, butylmagnesium hydride, hexylmagnesiumhydride, phenylmagnesium hydride, and benzylmagnesium hydride),hydrocarbylmagnesium halide (e.g., methylmagnesium chloride,ethylmagnesium chloride, butylmagnesium chloride, hexylmagnesiumchloride, phenylmagnesium chloride, benzylmagnesium chloride,methylmagnesium bromide, ethylmagnesium bromide, butylmagnesium bromide,hexylmagnesium bromide, phenylmagnesium bromide, and benzylmagnesiumbromide), hydrocarbylmagnesium carboxylate (e.g., methylmagnesiumhexanoate, ethylmagnesium hexanoate, butylmagnesium hexanoate,hexylmagnesium hexanoate, phenylmagnesium hexanoate, and benzylmagnesiumhexanoate), hydrocarbylmagnesium alkoxide (e.g., methylmagnesiumethoxide, ethylmagnesium ethoxide, butylmagnesium ethoxide,hexylmagnesium ethoxide, phenylmagnesium ethoxide, and benzylmagnesiumethoxide), and hydrocarbylmagnesium aryloxide (e.g., methylmagnesiumphenoxide, ethylmagnesium phenoxide, butylmagnesium phenoxide,hexylmagnesium phenoxide, phenylmagnesium phenoxide, and benzylmagnesiumphenoxide).

Many species of a formula (I) complex having an R² group which bonds toor associates with M via a C atom can be used in a catalyst compositionwithout an alkylating agent.

The catalyst composition also or alternatively can contain anon-coordinating anion or a non-coordinating anion precursor. Exemplarynon-coordinating anions include borate anions, particularly fluorinatedtetraarylborate anions. Specific examples of non-coordinating anionsinclude tetraphenylborate, tetrakis(monofluorophenyl) borate,tetrakis(difluorophenyl) borate, tetrakis(trifluororphenyl) borate,tetrakis(tetrafluorophenyl) borate, tetrakis(pentafluorophenyl) borate,tetrakis(tetrafluoromethylphenyl) borate, tetra(tolyl) borate,tetra(xylyl) borate, [tris(phenyl), pentafluorophenyl] borate,[tris(pentafluorophenyl), phenyl] borate,tridecahydride-7,8-dicarbaundecaborate and the like.Tetrakis(pentafluorophenyl) borate is among the preferrednon-coordinating anions.

Compounds containing a non-coordinating anion also contain acountercation such as a carbonium (e.g., tri-substituted carboniumcation such as triphenylcarbonium cation, tri(substitutedphenyl)carbonium cation (e.g., tri(methylphenyl)carbonium cation),oxonium, ammonium (e.g., trialkyl ammonium cations, N,N-dialkylanilinium cations, dialkyl ammonium cations, etc.), phosphonium (e.g.,triaryl phosphonium cations such as triphenyl phosphonium cation,tri(methylphenyl)phosphonium cation, tri(dimethylphenyl)phosphoniumcation, etc.), cycloheptatrieneyl, or ferrocenium cation (or similar).Among these, N,N-dialkyl anilinium or carbonium cations are preferred,with the former being particularly preferred.

Examples of compounds containing a non-coordinating anion and a countercation include triphenylcarbonium tetrakis(pentafluorophenyl)borate,N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,triphenylcarbonium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, andN,N-dimethylanilinium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate.

Exemplary non-coordinating anion precursors include boron compounds thatinclude strong electron-withdrawing groups. Specific examples includetriarylboron compounds where each aryl group is strongly electronwithdrawing, e.g., pentafluorophenyl or 3,5-bis(trifluoromethyl)phenyl.

Certain species of a formula (I) complex having an R² group which bondsto or associates with M via a C atom can be used in a catalystcomposition without a non-coordinating anion or a non-coordinating anionprecursor.

Catalyst compositions of the type just described have very highcatalytic activity for polymerizing polyenes such as conjugated dienes(and optionally olefins, particularly α-olefins including ethylene) intostereospecific polymers over a wide range of concentrations and ratios,although polymers having the most desirable properties typically areobtained from systems that employ a relatively narrow range ofconcentrations and ratios of ingredients. Further, the catalystcomposition ingredients are believed to interact to form an activecatalyst species, so the optimum concentration for each ingredient candepend on the concentrations of the other ingredients. The followingmolar ratios are considered to be relatively exemplary for a variety ofdifferent systems based on the foregoing ingredients:

-   -   alkylating agent to formula (I) complex: from ˜1:1 to ˜1000:1,        commonly from ˜2:1 to ˜500:1, typically from ˜5:1 to ˜200:1;    -   aluminoxane to formula (I) complex, specifically equivalents of        aluminum atoms in the aluminoxane to equivalents of Group 3        atoms in the complex: from ˜5:1 to ˜1000:1, commonly from ˜10:1        to ˜700:1, typically from ˜20:1 to ˜500:1;    -   organoaluminum compound to formula (I) complex: from ˜1:1 to        ˜200:1, commonly from ˜2:1 to ˜150:1, typically from ˜5:1 to        ˜100:1; and    -   non-coordinating anion or precursor to formula (I) complex: from        ˜1:2 to ˜20:1, commonly from ˜3:4 to ˜10:1, typically from ˜1:1        to ˜6:1.

The molecular weight of polymers produced with a formula (I)complex-containing catalyst composition can be impacted by adjusting theamount of metallic complex used and/or the amounts of co-catalystcompound concentrations within the catalyst composition; polymers havinga wide range of molecular weights can be produced in this manner. Ingeneral, increasing the metallic complex and co-catalyst concentrationsreduces the molecular weight of resulting polymers, although very lowmolecular weight polymers (e.g., liquid polydienes) require extremelyhigh catalyst concentrations. Typically, this necessitates removal ofcatalyst residues from the polymer to avoid adverse effects such asretardation of the sulfur cure rate.

A formula (I) complex-containing catalyst composition can be formedusing any of the following methods:

-   -   (1) In situ. The catalyst ingredients are added to a solution        containing monomer and solvent (or simply bulk monomer). The        addition can occur in a stepwise or simultaneous manner. In the        case of the latter, the alkylating agent preferably is added        first followed by the formula (I) complex.    -   (2) Pre-mixed. The ingredients can be mixed outside the        polymerization system, generally at a temperature of from about        −20° to ˜80° C., before being introduced to the monomer(s).    -   (3) Pre-formed in the presence of monomer(s). The catalyst        ingredients are mixed in the presence of a small amount of        monomer(s) at a temperature of from about −20° to ˜80° C. The        amount of monomer(s) can range from ˜1 to ˜500 moles, commonly        from ˜5 to ˜250 moles, typically from ˜10 to ˜100 moles, per        mole of the formula (I) complex. The resulting catalyst        composition is added to the remainder of the monomer(s) to be        polymerized.    -   (4) Two-stage procedure.        -   (a) The alkylating agent is combined with the formula (I)            complex in the absence of monomer or in the presence of a            small amount of monomer(s) at a temperature of from about            −20° to ˜80° C.        -   (b) The foregoing mixture and the remaining components are            charged in either a stepwise or simultaneous manner to the            remainder of the monomer(s) to be polymerized.            When a solution of one or more of the catalyst ingredients            is prepared outside the polymerization system in the            foregoing methods, an organic solvent or carrier preferably            is employed; useful organic solvents include those mentioned            previously. In other embodiments, one or more monomers can            be used as a carrier or the catalyst ingredients can be            employed neat, i.e., free of any solvent of other carrier.

In one or more embodiments, some or all of the catalyst composition canbe supported on an inert carrier. The support can be a porous solid suchas talc, a sheet silicate, an inorganic oxide or a finely dividedpolymer powder. Suitable inorganic oxides are oxides of elements fromany of Groups 2-5 and 13-16. Exemplary supports include SiO₂, aluminumoxide, and also mixed oxides of the elements Ca, Al, Si, Mg or Ti andalso corresponding oxide mixtures, Mg halides, styrene/divinylbenzenecopolymers, polyethylene or polypropylene.

Ordinarily skilled artisans recognize that varying the amounts of thecomponents of a catalyst composition (as well as the solvent system) cangreatly affect both the efficiency of the catalyst system as well as thecomposition and microstructure of the resulting polymer. For example,for catalyst compositions that include an alkylating agent as component(b), increasing the relative concentration of the alkylating agent mightresult in polymers with lower molecular weights (regardless of whethermeasured as M_(n), M_(w), or M_(p)) and/or less isolated polyene units,although the latter characteristic might be at least somewhat dependenton the composition of the solvent system (e.g., the effect might be moreevident in an aromatic solvent like toluene).

Similarly, the amount of time that the catalyst composition is permittedto contact the monomers can affect the size, mer composition and, to alesser extent, microstructure of the resulting polymer.

Further, the nature of the solvent system can affect both the processand the resulting polymer. For example, solvent systems made from one ormore alkanes often require higher concentrations of the catalystcomposition than do solvent systems consisting of other organicliquid(s). However, polymerization processes conducted in such solventsystems can yield interpolymers with higher amounts of olefin mer thancan an essentially identical process conducted in another type ofsolvent system, perhaps due to increased solubility of olefin monomer inan alkane-based solvent system.

Choice of M, m, n, z, R¹ and R² likewise can have major impacts onprocess and product characteristics. As a non-limiting example, formula(I)-type complexes where M is Gd and particularly Nd often yieldinterpolymers having higher levels of isolated polyene mer.

The production of polymers such as polydienes (or interpolymers thatinclude diene mer) is accomplished by polymerizing conjugated dienemonomer(s) in the presence of a catalytically effective amount of acatalyst composition as described above. The total catalystconcentration to be employed in the polymerization mass depends on theinterplay of multiple factors such as the purity of ingredients, thepolymerization temperature, the polymerization rate and conversiondesired, and the molecular weight desired. Accordingly, a specific totalcatalyst concentration cannot be definitively set forth except to saythat catalytically effective amounts of the respective catalystingredients should be used. The amount of the formula (I) complex usedgenerally ranges from ˜0.005 to ˜2 mmol, commonly from ˜0.01 to ˜1 mmol,typically from ˜0.02 to ˜0.5 mmol per 100 g monomer. All otheringredients generally can be added in amounts based on the amount offormula (I) complex; see the various ratios set forth above.

Where an olefin interpolymer is desired, the molar ratio of polyene(e.g., conjugated diene) to olefin introduced into the reaction vesselcan vary over a wide range. For example, the molar ratio of polyene(e.g., conjugated diene) to olefin can range from ˜100:1 to 1:100,commonly from ˜20:1 to 1:20, and typically from ˜5:1 to 1:5.

Polymerization preferably is carried out in one or more organic solventsof the type(s) set forth above, i.e., as a solution polymerization(where both the monomer(s) and the polymers formed are soluble in thesolvent) or precipitation polymerization (where the monomer is in acondensed phase but the polymer products are insoluble). The catalystingredients preferably are solubilized or suspended in the organicliquid, and additional solvent (beyond that used in preparing thecatalyst composition) usually is added to the polymerization system; theadditional solvent(s) may be the same as or different from thesolvent(s) used in preparing the catalyst composition. In one or moreembodiments, the solvent content of the polymerization mixture may bemore than 20%, more than 50%, or even more than 80% (by wt.) of thetotal weight of the polymerization mixture. The concentration of monomerpresent at the beginning of the polymerization generally ranges from ˜3to ˜80%, commonly from ˜5 to ˜50%, and typically from ˜10% to ˜30% (bywt.).

In certain embodiments, a bulk polymerization system that includes nomore than a minimal amount of solvent can be used, i.e., a bulkpolymerization process where one or more of the monomers act(s) as thesolvent; examples of potentially useful bulk polymerization processesare disclosed in U.S. Pat. No. 7,351,776. In a bulk polymerization, thesolvent content of the polymerization mixture may be less than ˜20%,less than ˜10%, or even less than ˜5% (by wt.) of the total weight ofthe polymerization mixture. The polymerization mixture even can besubstantially devoid of solvent, i.e., contain less than that amount ofsolvent which otherwise would have an appreciable impact on thepolymerization process.

The polymerization can be conducted in any of a variety of reactionvessels. For example, solution polymerizations can be conducted in aconventional stirred-tank reactor. Bulk polymerizations also can beconducted in a stirred-tank reaction if the monomer conversion is lessthan ˜60%. Where monomer conversion is higher than ˜60%, which typicallyresults in a highly viscous polymer cement (i.e., mixture of solvent,polymers and any remaining monomer(s)), bulk polymerization can beconducted in an elongated reactor in which the viscous cement is drivenby, for example, piston or self-cleaning single- or double-screwagitator.

All components used in or during the polymerization can be combined in asingle vessel (e.g., a stirred-tank reactor), and the entirety of thepolymerization process can be conducted in that vessel. Alternatively,two or more of the ingredients can be combined outside thepolymerization vessel and transferred to another vessel wherepolymerization of the monomer(s), or at least a major portion thereof,can be conducted.

Surprisingly, polymerizations performed in solvent systems that includeat least 50% (by wt.) of one or more C₅-C₁₀ alkanes (more expansivelydescribed above) can result in polyene/ethylene interpolymers having atleast 10 mole percent, 20 mole percent, 25 mole percent, 33 molepercent, 40 mole percent or even 50 mole percent ethylene mer. Thesehigh amounts of ethylene mer contents are believed to have beenpreviously unattainable in alkane-rich (or alkane-only) solvent systems.

Catalyst systems employing formula (I)-type complexes can result inpolymers having previously unattainable mer content distributions and/ormicrostructures, certain of which are described in the followingparagraphs (in which 1,3-butadiene is used as an exemplary polyene andethylene as an exemplary but preferred α-olefin).

Catalyst compositions employing certain embodiments of the indenyl-metalcomplex can yield copolymers with randomly distributed butadiene andethylene mer, but at least 40%, preferably at least 45% and morepreferably at least 50% of the butadiene mer are present in a cisisomeric configuration. Catalyst compositions employing certain otherembodiments of the indenyl-metal complex can yield copolymers with botha block of high cis butadiene mer (i.e., a block having the type of highcis isomeric configuration described in the preceding sentence) and ablock of randomly distributed butadiene and ethylene mer.

The polymerization can be carried out as a batch, continuous, orsemi-continuous process. The conditions under which the polymerizationproceeds can be controlled to maintain the temperature of thepolymerization mixture in a range of from −10° to ˜200° C., commonlyfrom ˜0° to ˜150° C., and typically from ˜20° to ˜100° C. Heat generatedby the polymerization can be removed by external cooling by a thermallycontrolled reactor jacket and/or internal cooling (by evaporation andcondensation of the monomer through use of a reflux condenser connectedto the reactor). Also, conditions may be controlled to conduct thepolymerization under a pressure of from ˜0.01 to ˜5 MPa, commonly from˜0.05 to ˜3 MPa, typically from ˜0.1 to ˜2 MPa; the pressure at whichthe polymerization is carried out can be such that the majority ofmonomers are in the liquid phase. In these or other embodiments, thepolymerization mixture may be maintained under anaerobic conditions,typically provided by an inert protective gas such as N₂, Ar or He.

Regardless of whether a batch, continuous, or semi-continuous process isemployed, the polymerization preferably is conducted with moderate tovigorous agitation.

The described polymerization process advantageously results in polymerchains that possess reactive (pseudo-living) terminals, which can befurther reacted with one or more functionalizing agents so as to providea polymer with a terminal functionality. These types of polymers can bereferred to as functionalized and are distinct from a propagating chainthat has not been similarly reacted. In one or more embodiments,reaction between the functionalizing agent and the reactive polymer canproceed via an addition or substitution reaction.

The terminal functionality can be reactive or interactive with otherpolymer chains (propagating and/or non-propagating) or with othermaterials in a rubber compound such as particulate reinforcing fillers(e.g., carbon black). As described above, enhanced interactivity betweena polymer and particulate fillers in rubber compounds improves themechanical and dynamic properties of resulting vulcanizates. Forexample, certain functionalizing agents can impart a terminalfunctionality that includes a heteroatom to the polymer chain; such afunctionalized polymer can be used in rubber compounds from whichvulcanizates can be provided, and that vulcanizates can possess hightemperature (e.g., 50° C.) hysteresis losses (as indicated by areduction in high temperature tan δ values) that are less than thosepossessed by vulcanizates prepared from similar rubber compounds that donot include such functionalized polymers. Reductions in high temperaturehysteresis loss can be at least 5%, at least 10%, or even at least 15%.

The functionalizing agent(s) can be introduced after a desired monomerconversion is achieved but prior to introduction of a quenching agent (acompound with a protic H atom) or after the polymerization mixture hasbeen partially quenched. The functionalizing agent can be added to thepolymerization mixture after a monomer conversion of at least 5%, atleast 10%, at least 20%, at least 50%, or at least 80%. In certainembodiments, the functionalizing agent is added after complete, orsubstantially complete, monomer conversion. In particular embodiments, afunctionalizing agent may be introduced to the polymerization mixtureimmediately prior to, together with, or after the introduction of aLewis base as disclosed in U.S. Pat. No. 8,324,329.

Useful functionalizing agents include compounds that, upon reaction,provide a functional group at the end of a polymer chain without joiningtwo or more polymer chains together, as well as compounds that cancouple or join two or more polymer chains together via a functionallinkage to form a single macromolecule. The ordinarily skilled artisanis familiar with numerous examples of terminal functionalities that canbe provided through this type of post-polymerization functionalizationwith terminating reagents, coupling agents and/or linking agents. Foradditional details, the interested reader is directed to any of U.S.Pat. Nos. 4,015,061, 4,616,069, 4,906,706, 4,935,471, 4,990,573,5,064,910, 5,153,159, 5,149,457, 5,196,138, 5,329,005, 5,496,940,5,502,131, 5,567,815, 5,610,227, 5,663,398, 5,567,784, 5,786,441,5,844,050, 6,812,295, 6,838,526, 6,992,147, 7,153,919, 7,294,680,7,642,322, 7,671,136, 7,671,138, 7,732,534, 7,750,087, 7,816,483,7,879,952, 8,063,153, 8,088,868, 8,183,324, 8,642,706, etc., as well asreferences cited in these patents and later publications citing thesepatents. Specific exemplary functionalizing compounds include metalhalides (e.g., SnCl₄), R¹⁰ ₃SnCl, R¹⁰ ₂SnCl₂, R¹⁰SnCl₃, metalloidhalides (e.g., SiCl₄), carbodiimides, ketones, aldehydes, esters,quinones, N-cyclic amides, N,N′-disubstituted cyclic ureas, cyclicamides, cyclic ureas, Schiff bases, iso(thio)cyanates, metalester-carboxylate complexes (e.g., dioxtyltin bis(octylmaleate),4,4′-bis(diethylamino) benzophenone, alkyl thiothiazolines,alkoxysilanes (e.g.,) Si(OR¹⁰)₄, R¹⁰Si(OR¹⁰)₃, R¹⁰ ₂Si(OR¹⁰)₂, etc.),cyclic siloxanes, alkoxystannates, and mixtures thereof. (In theforegoing, each R¹⁰ independently is a C₁-C₂₀ alkyl group, C₃-C₂₀cycloalkyl group, C₆-C₂₀ aryl group, or C₇-C₂₀ aralkyl group.) Commonlyused exemplary functionalizing compounds include SnCl₄, tributyl tinchloride, dibutyl tin dichloride, and 1,3-dimethyl-2-imidazolidinone(DMI).

The amount of functionalizing agent added to the polymerization mixturecan depend on various factors including the amount of formula (I)complex used, the type of functionalizing agent, the desired level offunctionality, etc. In one or more embodiments, the amount offunctionalizing agent may be in a range of from ˜1 to ˜200 moles,commonly from ˜5 to ˜150 moles, and typically from ˜10 to ˜100 moles permole of formula (I) complex.

Because reactive polymer chains slowly self-terminate at hightemperatures, the functionalizing agent can be added to thepolymerization mixture when or soon after a peak polymerizationtemperature is observed or, at least in some embodiments, within 30±10minutes thereafter. Reaction of these types of compounds with aterminally active polymer can be performed relatively quickly (a fewminutes to a few hours) at moderate temperatures (e.g., 0° to 75° C.).

The functionalizing agent can be introduced to the polymerizationmixture at a location (e.g., within a vessel) where the polymerization,or at least a portion thereof, has been conducted or at a locationdistinct therefrom. For example, the functionalizing agent can beintroduced to the polymerization mixture in downstream vessels includingdownstream reactors or tanks, in-line reactors or mixers, extruders, ordevolatilizers.

Although not mandatory, if desired, quenching can be performed toinactivate any residual reactive copolymer chains and the catalystcomposition. Quenching can be conducted by stirring the polymer and anactive hydrogen-containing compound, such as an alcohol or acid, for upto ˜120 minutes at temperatures of from 25° to ˜150° C. In someembodiments, the quenching agent can include a polyhydroxy compound asdisclosed in U.S. Pat. No. 7,879,958. An antioxidant such as2,6-di-t-butyl-4-methylphenol (BHT) may be added along with, before, orafter the addition of the quenching agent; the amount of antioxidantemployed can be from ˜0.2 to 1% (by wt.) of the polymer product. Thequenching agent and the antioxidant can be added neat or, if necessary,dissolved in a hydrocarbon solvent or liquid monomer prior to beingadded to the polymerization mixture.

Once polymerization, functionalization (if any) and quenching (if any)are complete, the various constituents of the polymerization mixture canbe recovered. Unreacted monomers can be recovered from thepolymerization mixture by, for example, distillation or use of adevolatilizer. Recovered monomers can be purified, stored, and/orrecycled back to the polymerization process.

The polymer product can be recovered from the polymerization mixtureusing known techniques. For example, the polymerization mixture can bepassed through a heated screw apparatus, such as a desolventizingextruder, in which volatile substances (e.g., low boiling solvents andunreacted monomers) are removed by evaporation at appropriatetemperatures (e.g., ˜100° to ˜170° C.) and under atmospheric orsub-atmospheric pressure. Another option involves steam desolvationfollowed by drying the resulting polymer crumbs in a hot air tunnel. Yetanother option involves recovering the polymer directly by drying thepolymerization mixture on a drum dryer. Any of the foregoing can becombined with coagulation with water, alcohol or steam; if coagulationis performed, oven drying may be desirable.

Recovered polymer can be grafted with other monomers and/or blended withother polymers (e.g., polyolefins) and additives to form resincompositions useful for various applications. The polymer, regardless ofwhether further reacted, is particularly suitable for use in themanufacture of various tire components including, but not limited to,tire treads, sidewalls, sub-treads, and bead fillers. It also can beused as a compatibilizer for elastomeric blends and/or used in themanufacture of hoses, belts, shoe soles, window seals, other seals,vibration damping rubber, and other industrial or consumer products.

When the resulting polymer is utilized in a tread stock compound, it canbe used alone or blended with any conventionally employed tread stockrubber including natural rubber and/or non-functionalized syntheticrubbers such as, e.g., one or more of homo- and interpolymers thatinclude just polyene-derived mer units (e.g., poly(butadiene),poly(isoprene), and copolymers incorporating butadiene, isoprene, andthe like), SBR, butyl rubber, neoprene, EPR, EPDM,acrylonitrile/butadiene rubber (NBR), silicone rubber, fluoroelastomers,ethylene/acrylic rubber, EVA, epichlorohydrin rubbers, chlorinatedpolyethylene rubbers, chlorosulfonated polyethylene rubbers,hydrogenated nitrile rubber, tetrafluoroethylene/propylene rubber andthe like. When a functionalized polymer(s) is blended with conventionalrubber(s), the amounts can vary from ˜5 to ˜99% of the total rubber,with the conventional rubber(s) making up the balance of the totalrubber.

When the resulting polymer is utilized in a tread stock compound, it canbe used alone or blended with any conventionally employed tread stockrubber including natural rubber and/or non-functionalized syntheticrubbers such as, e.g., one or more of homo- and interpolymers thatinclude just polyene-derived mer units (e.g., poly(butadiene),poly(isoprene), and copolymers incorporating butadiene, isoprene, andthe like), SBR, butyl rubber, neoprene, EPR, EPDM,acrylonitrile/butadiene rubber (NBR), silicone rubber, fluoroelastomers,ethylene/acrylic rubber, EVA, epichlorohydrin rubbers, chlorinatedpolyethylene rubbers, chlorosulfonated polyethylene rubbers,hydrogenated nitrile rubber, tetrafluoroethylene/propylene rubber andthe like. When a functionalized polymer(s) is blended with conventionalrubber(s), the amounts can vary from ˜5 to ˜99% of the total rubber,with the conventional rubber(s) making up the balance of the totalrubber.

Amorphous silica (SiO₂) can be utilized as a filler. Silicas aregenerally classified as wet-process, hydrated silicas because they areproduced by a chemical reaction in water, from which they areprecipitated as ultrafine, spherical particles. These primary particlesstrongly associate into aggregates, which in turn combine less stronglyinto agglomerates. “Highly dispersible silica” is any silica having avery substantial ability to de-agglomerate and to disperse in anelastomeric matrix, which can be observed by thin section microscopy.

Surface area gives a reliable measure of the reinforcing character ofdifferent silicas; the Brunauer, Emmet and Teller (“BET”) method(described in J. Am. Chem. Soc., vol. 60, p. 309 et seq.) is arecognized method for determining surface area. BET surface area ofsilicas generally is less than 450 m²/g, and useful ranges of surfaceinclude from ˜32 to ˜400 m²/g, ˜100 to ˜250 m²/g, and ˜150 to ˜220 m²/g.

The pH of the silica filler is generally from ˜5 to ˜7 or slightly over,preferably from ˜5.5 to ˜6.8.

Some commercially available silicas which may be used include Hi-Sil™215, Hi-Sil™ 233, and Hi-Sil™ 190 (PPG Industries, Inc.; Pittsburgh,Pa.). Other suppliers of commercially available silica include GraceEngineered Materials (Baltimore, Md.), Evonik Industries (Parsippany,N.J.), Solvay (Cranbury, N.J.), and J.M. Huber Corp. (Edison, N.J.).

Silica can be employed in the amount of 1 to 100 phr, commonly in anamount from ˜5 to ˜80 phr. The useful upper range is limited by the highviscosity that such fillers can impart.

Other useful fillers include all forms of carbon black including, butnot limited to, furnace black, channel blacks and lamp blacks. Morespecifically, examples of the carbon blacks include super abrasionfurnace blacks, high abrasion furnace blacks, fast extrusion furnaceblacks, fine furnace blacks, intermediate super abrasion furnace blacks,semi-reinforcing furnace blacks, medium processing channel blacks, hardprocessing channel blacks, conducting channel blacks, and acetyleneblacks; mixtures of two or more of these can be used. Carbon blackshaving a surface area (EMSA) of at least 20 m²/g, preferably at least˜35 m²/g, are preferred; surface area values can be determined by ASTMD-1765 using the CTAB technique. The carbon blacks may be in pelletizedform or an unpelletized flocculent mass, although unpelletized carbonblack can be preferred for use in certain mixers.

The amount of carbon black can be up to ˜50 phr, with 5 to 40 phr beingtypical. When carbon black is used with silica, the amount of silica canbe decreased to as low as ˜1 phr; as the amount of silica decreases,lesser amounts of the processing aids, plus silane if any, can beemployed.

Elastomeric compounds typically are filled to a volume fraction, whichis the total volume of filler(s) added divided by the total volume ofthe elastomeric stock, of ˜25%; accordingly, typical (combined) amountsof reinforcing fillers, i.e., silica and carbon black, is ˜30 to 100phr.

When silica is employed as a reinforcing filler, addition of a couplingagent such as a silane is customary so as to ensure good mixing in, andinteraction with, the elastomer(s). Generally, the amount of silane thatis added ranges between ˜4 and ˜20%, based on the weight of silicafiller present in the elastomeric compound.

Coupling agents generally include a functional group capable of bondingphysically and/or chemically with a group on the surface of the silicafiller (e.g., surface silanol groups) and a functional group capable ofbonding with the elastomer, e.g., via a sulfur-containing linkage. Suchcoupling agents include organosilanes, in particular polysulfurizedalkoxysilanes (see, e.g., U.S. Pat. Nos. 3,873,489, 3,978,103,3,997,581, 4,002,594, 5,580,919, 5,583,245, 5,663,396, 5,684,171,5,684,172, 5,696,197, etc.) or polyorganosiloxanes. An exemplarycoupling agent is bis[3-(triethoxysilyl)propyl]tetrasulfide.

Addition of a processing aid can be used to reduce the amount of silaneemployed. See, e.g., U.S. Pat. No. 6,525,118 for a description of fattyacid esters of sugars used as processing aids. Additional fillers usefulas processing aids include, but are not limited to, mineral fillers,such as clay (hydrous aluminum silicate), talc (hydrous magnesiumsilicate), and mica as well as non-mineral fillers such as urea andsodium sulfate. Preferred micas contain principally alumina, silica andpotash, although other variants also can be useful. The additionalfillers can be utilized in an amount of up to ˜40 phr, typically up to˜20 phr.

Other conventional rubber additives also can be added. These include,for example, process oils, plasticizers, anti-degradants such asantioxidants and antiozonants, curing agents and the like.

All of the ingredients can be mixed using standard equipment such as,e.g., Banbury or Brabender mixers. Typically, mixing occurs in two ormore stages. During the first stage (often referred to as themasterbatch stage), mixing typically is begun at temperatures of 120° to130° C. and increases until a so-called drop temperature, typically163°±3° C., is reached.

Where a formulation includes silica, a separate re-mill stage often isemployed for separate addition of the silane component(s). This stageoften is performed at temperatures similar to, although often slightlylower than, those employed in the masterbatch stage, i.e., ramping from˜90° C. to a drop temperature of ˜150° C.

Reinforced rubber compounds conventionally are cured with ˜0.2 to ˜5 phrof one or more known vulcanizing agents such as, for example, sulfur orperoxide-based curing systems. For a general disclosure of suitablevulcanizing agents, the interested reader is directed to an overviewsuch as that provided in Kirk-Othmer, Encyclopedia of Chem. Tech., 3ded., (Wiley Interscience, New York, 1982), vol. 20, pp. 365-468.Vulcanizing agents, accelerators, etc., are added at a final mixingstage. To ensure that onset of vulcanization does not occur prematurely,this mixing step often is done at lower temperatures, e.g., starting at˜60° to ˜65° C. and not going higher than ˜105° to ˜110° C.

The following non-limiting, illustrative examples provide the readerwith detailed conditions and materials that can be useful in thepractice of the present invention.

EXAMPLES

Indene, chlorotrimethylsilane, tert-butyldimethylsilyl chloride,tribenzylsilyl chloride, benzyldimethylsilyl chloride and n-butyllithiumwere purchased from Sigma-Aldrich (St. Louis, Mo.),N,N-dimethylanilinium tetra(pentafluorophenyl)borate from AlbemarleCorp. (Baton Rouge, La.), and trityltetra(pentafluorophenyl)borate fromStrem Chemicals, Inc. (Newburyport, Mass.).

Literature methods were used to prepare the following compounds:

-   -   1-tert-butyldimethylsilylindene, 1,3-bis(trimethylsilyl)indene        and 1,3-bis(tert-butyldimethylsilyl)indene: A. Davison et        al., J. Organomet. Chem., 23(2), pp. 407-26 (1970) and C. A.        Bradley et al., Organometallics, 23, pp. 5332-46 (2004),    -   gadolinium(III) tris[N,N-bis(trimethylsilyl)amide]: D. C.        Bradley et al., J. Chem. Soc., Chem. Commun., pp. 349-50 (1972),        and    -   di(octadecyl)methylammonium tetrakis(pentafluorophenyl)borate:        U.S. Pat. No. 5,919,983 (Rosen et al.).

In the chemical structures that follow, “Me” represents a methyl group.

Example 1a: 1-tribenzylsilylindene

To an oven-dried 500 mL Schlenk flask cooled under a stream of Ar wasadded 200 mL dry THF followed by 1.64 g (14.1 mmol) indene. Thissolution was cooled to −78° C. before dropwise addition over ˜5 minutesof 9.29 mL of a 1.55 M solution of n-butyllithium in hexanes. Thecontents were stirred at this temperature for ˜10 minutes.

The flask was transferred to an ice bath, and the contents were stirredfor another ˜30 minutes before 5.0 g (14.8 mmol) tribenzylsilyl chloridewas added in one portion. After removal of the ice bath, the flaskcontents were allowed to warm to room temperature before being stirredfor an additional ˜16 hours.

Volatiles were removed, re-dissolved into hexanes and washed with 20 mLof a saturated Na₂CO₃ solution. The organic layer was separated, driedover MgSO₄ and concentrated on a rotary evaporator. The residue wassubsequently purified under reduced pressure (˜13.3 Pa, 0.1 torr) firstto remove unreacted indene and then to isolate the desired product,1-tribenzylsilylindene (4.3 g, ˜40% yield).

Example 1b: 1-benzyldimethylsilylindene

To an oven-dried 500 mL Schlenk flask cooled under a stream of Ar wasadded 200 mL dry THF followed by 3.0 g (25.8 mmol) indene. This solutionwas cooled to −78° C. before dropwise addition over ˜5 minutes of 16.9mL of a 1.55 M solution of n-butyllithium in hexanes. The contents werestirred at this temperature for ˜10 minutes.

The flask was transferred to an ice bath, and the contents were stirredfor another ˜30 minutes before 5.0 g (27.2 mmol) benzyldimethylsilylchloride was added in one portion. After removal of the ice bath, theflask contents were allowed to warm to room temperature before beingstirred for an additional ˜16 hours.

Volatiles were removed, re-dissolved into hexanes and washed with 20 mLof a saturated Na₂CO₃ solution. The organic layer was separated, driedover MgSO₄ and concentrated on a rotary evaporator. The residue wassubsequently purified under reduced pressure (˜13.3 Pa, 0.1 torr) firstto remove unreacted indene and then to isolate the desired product,1-benzyldimethylsilylindene (6.2 g, ˜92% yield).

Example 2a: Complex With 1-tribenzylsilylindenyl ligand

Under Ar, 15 mL of a hexane solution of the compound prepared in Example1a (0.627 g, 1.5 mmol) was dropwise added to 15 mL of a solution of 1.00g (1.6 mmol) Gd(III){N[Si(CH₃)₃]₂}₃ (hereinafter “Gd[N(TMS)₂]₃”) inhexane. This mixture was stirred at 80° C. overnight (˜14 hours), duringwhich time a yellow solution formed.

The reaction vessel was cooled to room temperature before all volatileswere removed under vacuum.

The product recovered was 1.34 g (˜100% yield) of an off-whitecrystalline solid having the following structure:

Example 2b: Complex With 1-benzyldimethylsilylindenyl ligands

Under Ar, to a 30 mL solution of the compound prepared in Example 1b(1.22 g, 4.6 mmol) and 1.50 g (2.35 mmol) Gd[N(TMS)₂]₃ in hexane wasslowly added 2.22 mL 1,1,3,3-tetramethyldisilazane (1.25 g, 12.5 mmol).A small amount of white precipitate formed quickly.

This mixture was stirred at 80° C. overnight (˜14 hours) before the paleyellow solution was transferred to a flask under Ar. Solvent was removedunder vacuum, resulting in the recovery of 1.92 g (˜100% yield) of, as apale yellow oil:

Example 2c: Complex With 1-tert-butyldimethylsilylindenyl ligands

Under Ar, to a 30 mL solution of 1-tert-butyldimethylsilylindene (1.415g, 6.1 mmol) and 2.00 g (3.1 mmol) Gd[N(TMS)₂]₃ in hexane was slowlyadded 2.22 mL 1,1,3,3-tetramethyldisilazane (1.67 g, 12.5 mmol). A smallamount of white precipitate formed quickly.

This mixture was stirred at 80° C. overnight (˜14 hours) before theorange solution was transferred to a flask under Ar. Solvent was removedunder vacuum, resulting in the recovery of 2.30 g (˜93% yield) of, as ared oil:

Example 2d: Complex With 1,3-bis(tert-butyldimethylsily)indenyl ligands

The reaction from Example 2c was repeated except that 2.116 g (6.1 mmol)1,3-bis(tert-butyldimethylsilyl)indene was used in place of1-tert-butyldimethylsilylindene.

This mixture was stirred at 80° C. overnight (˜12 hours) before the paleyellow solution was transferred to a flask under Ar. Solvent was removedunder vacuum, resulting in the recovery of 3.00 g (˜100% yield) of, as ayellow oil:

Example 2e: Complex With 1,3-bis(trimethylsilyl)indenyl ligands

The process from Example 2d was repeated except that 1.600 g (6.1 mmol)1,3-bis(trimethylsilyl)indene was used in place of1,3-bis(tert-butyldimethylsilyl)indene. The product recovered was 2.46 g(˜99% yield) of, as a yellow oil:

Examples 2f-2h: Additional Complexes

Using procedures similar to those described above, the followingadditional complexes also were prepared:

Each of the complexes from Examples 2a-2h was used to prepare a catalystfor at least one polymerization of butadiene and ethylene.

To assist in comparing the effects of the complexes as catalystcomponents, the monomers that underwent polymerization and many othervariables were held constant; however, this should not be considered tobe limiting. Monoethylenically unsaturated monomers (e.g., α-olefins)other than ethylene and polyenes other than butadiene certainly can beused alternatively or additionally. Other parameters of thepolymerization also can be changed.

Examples 3-7: Copolymerizations Using Formula (IIa) Complex-ContainingCatalysts

Except as noted below, the following procedure was used in each of thepolymerizations.

To a dry, N₂-purged stainless steel 5 L vessel was added dry solvent(1.80 kg toluene or 1.77 kg hexane—see Table 1) and varying amounts (seeTable 1) of purified, dry 1,3-butadiene before the reactor waspressurized to 0.2 MPa with ethylene. The reactor agitator wasinitiated, the jacket was heated to 50° C., and the reactor contentswere allowed to equilibrate to that temperature.

During equilibration, a 200 mL bottle that was previously dried andN₂-purged was placed in an Ar glovebox. To this bottle was added 50 mLdry solvent followed by varying amounts (see Table 1 below) of a1.02±0.05 M solution of DIBAH in solvent, formula II(a) complex, andfinally varying amounts (see Table 1 below) of either:

-   -   (1) where toluene was used as solvent, varying amounts of solid        N,N-dimethylanilinium tetra(pentafluorophenyl)borate (DEATPFPB),        or    -   (2) where hexane was used as solvent, varying amounts of a        0.0326 M solution of di(octadecyl)methylammonium        tetrakis(pentafluorophenyl)borate in cyclohexane.        The mixture was sealed and removed from the glovebox.

The contents of the small bottle were injected into the reactor, andgaseous dried ethylene was allowed to fill the reactor to a finalpressure of 1.72 MPa. The jacket temperature of the reactor wasincreased (see Table 1 below).

After varying amounts of time (see Table 1 below), each polymer cementwas dropped into a vat of 2-propanol containing2,6-di-tert-butyl-4-methylphenol.

Recovered polymer was drum dried at 120° C.

The amounts of polymer, mer content and other properties also aresummarized below in Table 1. Mole percentages were calculated from ¹Hand ¹³C NMR spectroscopic data, while molecular weight information wasdetermined by high temperature GPC.

TABLE 1 Catalyst information and polymer properties, formula (IIa)-typecomplex 3 4 5 6 7 Amt. of complex, mmol 0.045 0.045 0.045 0.138 0.138Amt. borate, mmol 0.0473 0.0473 0.0473 0.145 0.145 Amt. DIBAH, mmol 3.63.6 1.8 6.1 3.0 Catalyst aging time (min.) 20 20 15 0 0 Solvent toluenetoluene toluene hexane hexane Amt. 1,3-BD (g), reactor 200 200 200 230230 Polymerization temp. (° C.) 80 120 100 100 100 Polymerization time,min. 120 50 180 122 180 Amt. of polymer, g 295 221 148 236 288 ethylenemer, mol % 47.3 44.5 55.9 53.7 67.2 butadiene mer, mol % 52.7 55.5 44.146.3 32.8 cis-1,4 BD mer, % 57.8 51.2 92.1^(a) 94.7^(a) 91.6^(a)trans-1,4 BD mer, % 38.1 44.3 1,2-vinyl BD mer, % 4.1 4.5 7.9 5.3 8.4isolated BD mer, % 32 29 60 48 79 M_(n) (kg/mol) 43.3 49.5 101.8 53.173.9 M_(w)/M_(n) 7.3 4.7 5.8 12.6 10.2 1st T_(m) (° C.) 52.4 47.9 −16.818.3 15.5 2nd T_(m) (° C.) n/a n/a 16.1 46.2 45.3 3rd T_(m) (° C.) n/an/a 46.7 n/a n/a ^(a)Isomerism not determined, with combined amount ofmer having 1,4-microstructure listed in table.

A 6.05 mg portion of the polymer from Example 3 was tested by DSC over atemperature range of −150° to ˜200° C., the results of which are shownin FIG. 1. The presence of a melting point indicates that theinterpolymer includes a block (i.e., is not fully alternating orrandom), its location on the curve (T≈50° C.) tends to suggest that theblock contains both butadiene and ethylene mer, and its broad naturesuggests mer randomness and asymmetry. (Blocks that are all (oressentially all) butadiene mer have a T_(m)≈−15° C., while blocks thatare all (or essentially all) ethylene mer have a T_(m)≈120° C. In eachcase, the “approximately equal” symbol should be read as a range of5-10° C. on each side of the stated value.)

Other portions of the polymer from Example 3 were dissolved indeuterated tetrachloroethane and subjected to NMR spectroscopy, usingthe settings shown below:

TABLE 2 NMR spectrometer settings ¹H ¹³C Sample temp. (° C.) 120 120Acquisition time (sec) 4.0 2.0 Frequency (MHz) 300.06 75.46 Spectrumoffset (Hz) 1796.60 7907.60 Sweep width (Hz) 4803.07 18115.94 Receivergain 24.0 30.0

The ¹H NMR spectrograph is shown in FIG. 2. The peak centered at achemical shift of ˜1.95-1.97 ppm is believed to represent so-calledisolated butadiene mer, i.e., butadiene mer that is not part of a blockor microblock of butadiene mer and, instead, sandwiched by ethylene mer.

The ¹³C NMR spectrograph is shown in FIG. 3. The peaks centered atchemical shifts of ˜32.1 and ˜32.2 ppm are believed to represent thepresence of the same isolated butadiene mer discussed in the precedingparagraph.

(The integrations of the noted peaks from these NMR spectrographsrelative to the sum of integrations of all peaks attributable tobutadiene mer were used to calculate the isolated butadiene mer in Table1 above.)

Examples 8-15: Copolymerizations Using Catalysts Containing Formula(IIb)-(IIe) Complexes

The process from Examples 3-7 was essentially repeated except as notedbelow.

The polymerization of Example 10 was modified by including 0.25 g1,3-butadiene to the catalyst composition bottle prior to addition ofthe DIBAH solution.

The polymerizations of Examples 13 and 15 employed 5.78 mL of 1.05 Msolution of DIBAH in hexane and 4.45 mL of a 0.0326 Mdi(octadecyl)methylammonium tetrakis(pentafluorophenyl)borate solutionin cyclohexane was used rather than the DEATPFPB solution.

Conditions and polymer properties are summarized below in Table 3.

TABLE 3 Catalyst information and polymer properties 8 9 10 11 12 13 1415 complex (IIb) (IIb) (IIb) (IIc) (IId) (IId) (IIe) (IIe) Amt. ofcomplex, mmol 0.045 0.045 0.045 0.045 0.045 0.045 0.138 0.138 Amt.borate, mmol 0.0473 0.0473 0.0473 0.0473 0.0473 0.0473 n/a n/a Amt.DIBAH, mmol 3.6 3.6 3.6 3.6 3.6 6.1 3.9 6.1 Catalyst aging time (min.)20 20 60 20 20 0 20 0 Solvent toluene toluene toluene toluene toluenehexane toluene hexane Amt. 1,3-BD (g), reactor 200 200 200 200 200 230216 230 Polymerization temp. (° C.) 80 80 80 80 80 80 80 80Polymerization time, min. 120 180 180 120 120 120 120 120 Amt. ofpolymer, g 100 282 291 240 220 245 232 235 ethylene mer, mol % 39.5 47.553.9 27.9 21.2 26.5 23.5 17.5 butadiene mer, mol % 60.5 52.5 46.1 72.178.8 73.5 76.5 82.5 cis-1,4 BD mer, % 48.7 58.9 46.1 98.2^(b) 97.1^(b)96.4^(b) 97.8^(b) 97.1^(b) trans-1,4 BD mer, % 43.9 35.8 48.1 1,2-vinylBD mer, % 7.4 5.3 5.8 1.8 2.9 3.6 2.2 2.9 isolated BD mer, % 42 34 46 <1<1 <1 <1 5 M_(n) (kg/mol) 64.4 81.2 61.6 76.2 59.5 34.9 61.5 39.6M_(w)/M_(n) 13.5 11.2 12.6 10.2 7.3 10.6 8.3 13.0 1st T_(m) (° C.) −12.6−15.2 −15.2 −11.5 −13.2 −14.0 −10.9 −12.7 2nd T_(m) (° C.) 16.8 40.717.6 121.4 124.4 117.4 124.4 114.8 3rd T_(m) (° C.) 43.8 n/a 42.8 n/an/a n/a n/a n/a ^(b)Isomerism not determined, with combined amount ofmer having 1,4-microstructure listed in table.

Portions of the polymers from Examples 8-10 were tested by DSC over atemperature range of −150° to ˜200° C. The presence of multiple meltingpoints indicated the possible presence of multiple blocks, with a peakat T≈−15° C. suggesting a block of butadiene mer and a peak at T≈40°-45°C. suggesting a block that contains both butadiene and ethylene mer. Theamount of isolated butadiene mer for each of these polymers (see Table 3above) might suggest that this latter black includes randomlydistributed, if not alternating, mer.

Examples 16-20: Copolymerizations Using Formula (IIf) Complex-ContainingCatalysts

The process from Examples 3-7 was essentially repeated.

Conditions and polymer properties are summarized below in Table 4.

TABLE 4 Catalyst information and polymer properties, formula (IIf)-typecomplex 16 17 18 19 20 Amt. of complex, 0.138 0.138 0.138 0.045 0.060mmol Amt. borate, mmol 0.145 0.145 0.145 0.0473 0.063 Amt. DIBAH, mmol6.1 6.1 3.0 3.6 3.0 Catalyst aging time 0 0 0 15 15 (min.) Solventhexane hexane hexane toluene toluene Amt. 1,3-BD (g), 230 230 230 200200 reactor Polymerization temp. 100 100 100 85 85 (° C.) Polymerizationtime, 120 180 244 180 240 min. Amt. of polymer, g 196 392 215 126 288ethylene mer, mol % 61.3 65.8 63.7 56.8 51.7 butadiene mer, mol % 30.734.2 36.3 43.2 48.3 1,4 BD mer, % 93.7 93.9 93.5 91.1 94.3 1,2-vinyl BDmer, % 6.3 6.1 6.5 8.9 5.7 isolated BD mer, % 80 85 83 70 86 M_(n)(kg/mol) 43.9 47.6 72.8 63.7 82.3 M_(w)/M_(n) 6.4 8.5 7.9 4.0 4.0 1stT_(m) (° C.) 15.3 17.0 17.4 −15.0 −15.2 2nd T_(m) (° C.) 47.9 50.0 51.231.2 32.0 3rd T_(m) (° C.) n/a n/a n/a 97.7 44.5

In the polymer from Example 19, the presence of a melting point atT≈100° C. suggests the presence of a block of ethylene mer.

A DSC plot over a temperature range of −150° to ˜200° C. for a 3.83 mgsample of the polymer of Example 16 is shown in FIG. 4. The presence ofdistinct melting points indicates that the interpolymer includes blocks,and the location of the second one on the curve (T≈45°-50° C.) tends tosuggest a block that contains both butadiene and ethylene mer.

Other portions of the polymer from Example 16 were dissolved indeuterated tetrachloroethane and subjected to NMR spectroscopy, usingthe settings shown below:

TABLE 5 NMR spectrometer settings ¹H ¹³C Sample temp. (° C.) 120 120Acquisition time (sec) 2.0 2.0 Frequency (MHz) 300.06 75.46 Spectrumoffset (Hz) 1796.60 7907.02 Sweep width (Hz) 4803.07 18115.94 Receivergain 22.0 30.0

The ¹H NMR and ¹³C NMR spectrographs are shown in, respectively, FIGS. 5and 6. The large peaks at approximately the same chemical shiftsdiscussed above in connection with FIGS. 2 and 3 are believed toindicate an extremely high level of isolated butadiene mer.

Examples 21-22: Copolymerizations Using Formula (IIg) Complex-ContainingCatalysts

The process from Examples 3-7 was essentially repeated.

Conditions and polymer properties are summarized below in Table 6.

TABLE 6 Catalyst information and polymer properties, formula (IIg)-typecomplex 21 22 Amt. of complex, mmol 0.045 0.138 Amt. borate, mmol 0.04730.145 Amt. DIBAH, mmol 3.6 6.1 Catalyst aging time (min.) 20 0 Solventtoluene hexane Amt. 1,3-BD (g), reactor 200 230 Polymerization temp. (°C.) 80 100 Polymerization time, min. 60 120 Amt. of polymer, g 256 367ethylene mer, mol % 49.2 63.3 butadiene mer, mol % 50.8 36.7 1,4 BD mer,% 95.0 94.4 cis configuration, % x 12.1 trans configuration, % x 82.21,2-vinyl BD mer, % 5.0 5.6 isolated BD mer, % 37 75 M_(n) (kg/mol) 32.145.9 M_(w)/M_(n) 16.3 7.8 1st T_(m) (° C.) −16.2 12.5 2nd T_(m) (° C.)19.4 47.0 3rd T_(m) (° C.) 43.8 107.0 4th T_(m) (° C.) 107.6 n/a

In both of the polymers, the presence of a melting point at T>100° C.suggests the presence of a block of ethylene mer.

Examples 23-25: Copolymerizations Using Formula (IIh) Complex-ContainingCatalysts

The process from Examples 3-7 again was essentially repeated.

Conditions and polymer properties are summarized below in Table 7.

TABLE 7 Catalyst information and polymer properties, formula (IIh)-typecomplex 23 24 25 Amt. of complex, mmol 0.045 0.138 0.138 Amt. borate,mmol 0.0473 0.210 0.145 Amt. DIBAH, mmol 3.6 6.1 6.1 Catalyst aging time(min.) 20 0 0 Solvent toluene hexane hexane Amt. 1,3-BD (g), reactor 200230 230 Polymerization temp. (° C.) 100 100 100 Polymerization time,min. 135 240 330 Amt. of polymer, g 95 164 244 ethylene mer, mol % 39.547.5 51.0 butadiene mer, mol % 60.5 52.5 49.0 1,4 BD mer, % 94.3 94.294.3 1,2-vinyl BD mer, % 5.7 5.8 5.7 isolated BD mer, % 59 82 86 M_(n)(kg/mol) 99.2 43.0 48.0 M_(w)/M_(n) 3.7 8.7 9.2 1st T_(m) (° C.) 32.331.3 50.2 2nd T_(m) (° C.) 47.3 43.7 n/a 3rd T_(m) (° C.) n/a 100.4 n/a

A DSC plot over a temperature range of −150° to ˜200° C. for a 4.08 mgsample of the polymer of Example 24 is shown in FIG. 7. The presence ofa relatively broad melting point at T≈40°-60° C. indicates a block thatcontains both butadiene and ethylene mer, likely one that involvessignificant randomness and, perhaps, asymmetry.

Other portions of the polymer from Example 24 were dissolved indeuterated tetrachloroethane and subjected to NMR spectroscopy, usingthe settings shown below:

TABLE 8 NMR spectrometer settings ¹H ¹³C Sample temp. (° C.) 120 120Acquisition time (sec) 2.0 2.0 Frequency (MHz) 300.06 75.46 Spectrumoffset (Hz) 1796.60 7907.44 Sweep width (Hz) 4803.07 18115.94 Receivergain 28.0 30.0

The ¹H NMR and ¹³C NMR spectrographs are shown in, respectively, FIGS. 8and 9. The large peaks at approximately the same chemical shiftsdiscussed above in connection with FIGS. 2 and 3 are believed toindicate an extremely high level of isolated butadiene mer.

That which is claimed is:
 1. An interpolymer comprising conjugated dienemer and from 40 to 75 mole percent ethylene mer, a plurality of saidethylene mer being randomly distributed and some of said conjugateddiene mer forming at least one block, wherein at least one of thefollowing is true of said interpolymer: a ¹³C nuclear magnetic resonancespectroscopy plot thereof includes a peak at one or more of 32.1 ppm and32.2 ppm, and a proton nuclear magnetic resonance spectroscopy plotthereof includes a peak at between 1.85 and 2.02 ppm.
 2. Theinterpolymer of claim 1 wherein from more than zero to 10 mole percentof said conjugated diene mer are incorporated in a vinyl-1,2configuration.
 3. A composition comprising a) a solvent system thatcomprises at least 50% by weight of—one or more C₅-C₁₀ alkanes and b) aninterpolymer that comprises conjugated diene mer and at least 50 molepercent ethylene mer, at least some of said ethylene mer being randomlydistributed in said interpolymer and said interpolymer comprising atleast one block of said conjugated diene mer.
 4. The composition ofclaim 3 wherein 25 to 99 mole percent of said conjugated diene mer arerandomly distributed.
 5. The composition of claim 3 wherein from morethan zero to 10 mole percent of said conjugated diene mer areincorporated in a vinyl-1,2 configuration.
 6. The composition of claim 3wherein a plurality of said ethylene mer are randomly distributed insaid interpolymer.
 7. The composition of claim 3 wherein said solventsystem consists of one or more C₅-C₁₀ alkanes.
 8. The interpolymer ofclaim 1 wherein from 25 to 99 mole percent of said conjugated diene merare randomly distributed.
 9. An interpolymer comprising polyene mer andfrom 40 to 75 mole percent ethylene mer, a plurality of said ethylenemer being randomly distributed, wherein said interpolymer comprises atleast one block of polyene mer, wherein said polyene mer comprise dienemer, and wherein at least one of the following is true about saidinterpolymer: a ¹³C nuclear magnetic resonance spectroscopy plot thereofincludes a peak at one or more of 32.1 ppm and 32.2 ppm, and a protonnuclear magnetic resonance spectroscopy plot thereof includes a peak atbetween 1.85 and 2.02 ppm.